1. Field of the Invention
The present invention relates to novel pyrido (3,4-d)-pyridazine derivatives which have effective diuretic action.
2. Description of the Prior Art
There have been synthesized many kinds of diuretics, and some of them have been applied in practice, typical examples of which are chlorothiazide derivatives, acetazolamide, triamterene, trifrocine, furosemide, etc.
However, known diuretics are not very satisfactory in view of one or more of such disadvantages as promoting the excretion of potassium as well as sodium, causing side effects (e.g. increase of blood glucose level and blood uric acid level) upon long-term administration, and showing rather low diuretic activity and rather high toxicity.
The present inventors have sought to provide an effective diuretic which is unaccompanied by such disadvantages.